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Engineers Devise New Way to Produce Clean Hydrogen

31.05.2013

While hydrogen is ubiquitous in the environment, producing and collecting molecular hydrogen for transportation and industrial uses is expensive and complicated. Just as importantly, a byproduct of most current methods of producing hydrogen is carbon monoxide, which is toxic. The main problem is that carbon monoxide, which is not only toxic to life, but also quickly damages the catalyst on fuel cell membranes that are crucial to the functioning of a fuel cell, producing electricity through chemical reactions, most commonly involving hydrogen.

Duke University engineers have developed a novel method for producing clean hydrogen, which could prove essential to weaning society off of fossil fuels and their environmental implications. They, using a new catalytic approach, have shown in the laboratory that they can reduce carbon monoxide levels to nearly zero (less than 0.002 percent) and also demonstrated that hydrogen by reforming fuel could be produced at much lower temperatures than conventional methods, which makes it a more practical option. The researchers ran the reaction for more than 200 hours and found no reduction in the ability of the catalyst to reduce the amount of carbon monoxide in the hydrogen gas.

In this case, the catalysts were nanoparticle combinations of gold and iron oxide (rust), but not in the traditional sense. Current methods depend on gold nanoparticles ability to drive the process as the sole catalyst, while the Duke researchers made both the iron oxide and the gold the focus of the catalytic process. It had been assumed that the iron oxide nanoparticles were only 'scaffolds' holding the gold nanoparticles together, and that the gold was responsible for the chemical reactions. However, they found that increasing the surface area of the iron oxide dramatically increased the catalytic activity of the gold.

The mechanism for this is not exactly understood yet. However, while current thinking is that the size of the gold particles is key, the authors believe the emphasis of further research should focus on iron oxide's role in the process.